This invention relates to temporary retaining walls and methods for making the same adjacent property to be excavated in the future.
Excavations for buildings normally must be shored so that the sidewalls of the excavation do not cave in during construction of permanent load-bearing walls. One method for shoring the sidewalls of the excavation is to use soil nailing techniques. In the past, soil nailing techniques have utilized steel anchor rods that are inserted in holes drilled into the sidewall of the excavation. The holes are placed several feet apart in both the horizontal and vertical directions. These holes are then filled with a cementitious material such as grout that surrounds the steel anchor rod. A shoring wall is then formed, for example, by shot construction, against the side of the excavation and tied to the steel anchor rods and cementitious filler material. Normally, these shoring walls are built in four-foot to six-foot high increments as the excavation is dug deeper. The permanent load-bearing walls are then normally built from the bottom up on the inside of the shoring walls.
Almost always reinforcing rods and the surrounding concrete grout extend into rights-of-way adjacent to the building construction site. It is desirable to be able to excavate in these rights of way after the original building is finished. In many instances, it is desirable to excavate these adjacent rights-of-way or property. It is difficult to do so and very hard on excavating equipment when the steel rods are left in place. Thus, the steel rods are normally removed through the permanent load-bearing wall after it is completed. In order to do this, however, a hole must be left in the permanent wall. After the steel rods are removed through the hole, the hole must be patched with concrete and the resulting wall fully water sealed. This process leads to significant extra expense as well as complications in assuring waterproofing of the below ground load-bearing walls.
The present invention comprises a soil nailing system that extends into property adjacent an excavation that can later be excavated without encountering steel rod obstructions that can result in damage to excavation equipment. The soil nailing system includes a temporary retaining wall for the sidewall of the soil excavation. Soil nails are extended outwardly into the soil sidewall. The soil nails comprise an easily shearable reinforcing rod, preferably made of fiber reinforced polymer, surrounded by grout or other cementitious material. This grout or cementitious material is integrally tied to the temporary retaining wall for the soil excavation. Thereafter, a permanent cementitious wall is formed inwardly of the temporary retaining wall. This construction eliminates the need for removing the steel rods used in prior soil nailing techniques. In addition, the property adjacent the temporary retaining wall can easily be excavated with conventional excavating equipment without harm to the equipment or to the original retaining wall or associated permanent structure. Use of the invention leads to significant savings over the prior art methods that require steel rod removal, and also reduces the easement fees that must be paid to an adjacent landowner.